This invention relates to peak detector circuits, and more particularly to a tracking peak detector of the type used in communications circuits.
In communications circuits such as signal reception equipment used in local area networks or the like, it is often necessary to derive a threshold, or a number of thresholds, from a variable amplitude signal. The thresholds will change as the input signal changes. For example, in a communication channel, the length of the link can vary between installations, and thus the signal amplitude at the receiver will vary.
Various peak detector circuits have been previously described. For example, peak detector circuits are shown in U.S. Pat. Nos. 4,533,844, 4,605,867, 4,906,864, and 4,987,323. These prior circuits have been complex and expensive, have used circuit components not compatible with the integrated circuit devices typically used in high speed communications interfaces and computers, or otherwise have been less than optimum for use in the proposed environment. As used herein, a high speed communications interface sends data on the order of 100 Mbits/sec or more.